This is a single arm trial. All Patients will receive up to 6 cycles of triple chemotherapy with docetaxel, cisplatin and S-1. Given the severe toxicity of DCF regimen, here the total dose of docetaxel and cisplatin is both reduced to 60mg/m2. For patients with CR/PR/SD disease after 6 cycles of chemotherapy, maintenance therapy with S-1 are recommended. Antitumor activity will be evaluated every two cycles according to RECIST1.1.